Feeding mechanism for metal sheets



' A ril 23, 1940. H. w. THEISS FEEDING MECHANISM FOR METAL SHEETS Filed NW. 28, 1938 2 Sheets-Sheet 1 April 23, 1940. H. w. THEISS FEEDING MECHANISM FOR METAL SHEETS Filed Nov. 28, 1938 2 Sheets-Sheet 2 Patented Apr. 23, 1940 "UNITED STATES PATENT OFFlCE 2. FEEDING MECHANISM FOR METAL SHEETS f Harry W. Theiss, Louisville, Ohio, assignor to Continental Steel Corporation, Kokomo, Ind., a corporation of Indiana Application November 28, 1938, Serial No. 242,759

41-01mm. (o1. zi -26) The feeding mechanism of the present invention is designed primarily for use in feeding individual sheets forwardly for discharging intoa pickling tank, although obviously adapted for other purposes.

The object of the present invention is to pro.- vide coordinate mechanism'for first lifting and afterwards advancing the sheets singly in processional relation and in timed sequence by the unified action of vacuum cups and magnetic rolls so disposed in relation to one another as to accurately and evenly feed the sheets forwardly for further treatment or manipulation.

Further objects and details will appear from the description of the invention in conjunction with the accompanying drawings, wherein-- Figure 1 is a side elevation of the feeding mechanism of the present invention; and

Fig. 2' is a top plan view of the same.

The mechanism of the present invention is intended to feed forward the uppermost metal sheet from a stack I I) which is supported upon a platform I I, which is preferably adapted to be elevated in some suitable manner to compensate u for the progressive depletion of the stack as the sheets are fed singly therefrom.

The feeding mechanism comprises a group of flexible vacuum cups l2 adapted to expel air by contact and which as shown are four in mun- 3o ber.

and mounted at the lower ends of rods l3 which comprise'the legs of an inverted U-shaped frame member, the two frame. membersbeing united at their upper bends or turns by a header bar 35 II, which arrangement constitutes ,in effect a carrier 'frame having four legs each of which carries a vacuum cup; This arrangement provides for uniformcontact with the uppermost sheet at four widely separated points, so that a 40 uniform lifting actionis afforded which prevents slipping or saggingof the sheet during its period of' elevation and until it is brought into contact with a pair of magnetic rolls I5 carried by transversely extending shafts l6, which are operated in unison and invthe same direction by sprocket chains I! which engage companion sprocket wheels I 8 carried by a shaft l9 which carries a- The active feeding surfaces of theina'gnetic rolls are presented downwardly and at a'uniform level, and as shown the two forward vacuum cups.

occupy a position intermediate the magnetic rolls The vacuum cups are arranged in pairs while the two rear vacuum cups occupycorresponding positions behind-the rear roll. I

The header pipe llis carried by a piston rod 22 provided with a piston operating'within. a-

cylinder 23 having upper and lower pressure pipes 24 and 25 leading thereto, so that pressure may be admitted to either end of the cylinder to raise and lower the vacuum cup frame as thefeeding progresses. Since it is desirable to feed the metal sheets forwardly in a closely spaced procession, it, is necessary to provide means for regulating the flow of pressure so that the vacuum cups will be raised and lowered in timed relation to the intended feeding rate and a constant stream of sheets fed forward in sequence to a pair of feed rolls 26 whose biting plane is aligned with the lower surfaces of the magnetic rolls.'

As shown, the upper feeding roll 26 is journaled within journal blocks 21 each backed by a spring 28 which bears against a plate 29 adapted to be depressed by pressure admitted into a cylinder 30 from a pressure pipe 3!, so that uniform pressure may be maintained on the feed rolls 26, although these details do not form an essential part of the present invention.

In order to meet the requirements above noted and to register the passage ofeach sheet, any suitable trip mechanism may be employed; As shown, a contact roller 32 is provided which is mounted upon a pivoted arm 23 so disposed as to be held in elevated relation when a sheet is being fed forwardly and to fall to its lowermost position when the support previously afforded by the sheet is no longer present. This trip mechanism serves through suitable connec tions, which need not be described in detailgto actuate valve mechanism 34 for controlling the admission of pressure through the pipe 25 to the upper end of the cylinder 23 for-lowering the vacuum cups to make contact in unison with the top sheet of the stack. Similar mechanism having a trip roller 34 is provided, and when the roller is lowered after passage of a sheet or otherwise, such lowering serves to admit pressure through the pipe 24 to the end of the cylinder for lifting the sheet previously contacted by the vacuum cups and repeating these operations in timed sequence. The trip mechanism shown serves merely for purposes of illustration and need not be described in detail, since it forms no essential part of the present invention.

In operation, the stack of sheets is brought into position upon the platform H, and as soon as pressure is admitted to the cylinder through the pipe 25, the frame carrying the four vacuum cups will be lowered into contact with the uppermost sheet and since at this stage the trip roller 34a is lowered, the frame immediately thereafter will be elevated, which has the effect of lifting the forward end of the sheet into contact with the rotating magnetic rolls which strip the sheet from the vacuum cups and hold it elevated by overhead suspension in the plane of the bite of the rolls 26 and feed it forwardly until it reaches the bite of said feed rolls 26 which continue its advancement. The sheet being flexible will be flexed upwardlyand dragged forwardly from the stack, and by providing a plurality of points of vacuum contact, and by providing duplicate magnetic rolls in the feeding plane of the rolls 26, a firm and widely extended contact with the sheet will be maintained so that it will not be displaced or slewed sideways or defiected from a straight line forward course of ad- Vance by the drag of the rear portion of the sheet along the surface of the stack.

After the trailing end of the sheet has passed the trip roll 32 the roll will fall, which initiates another reciprocation of the vacuum cup frame and the elevation of the next succeeding sheet into contact with the pneumatic rolls, so that the feeding operation will proceed at closely spaced intervals and a procession of sheets will be maintained which are fed forward into the pickling tank or other receptacle or apparatus provided for their further manipulation.

By the employment of vacuum cups for initially lifting the sheets it is possible to elevate the magnetic l'Olls sufficiently above the top surface of the stack so that the sheets in the stack will not be subjected to appreciable magnetic influence, which will be effective only on single sheets when elevated to the point of actual contact with the'magnetic rolls. By locating the forward pair of vacuum cups in intermediate relation between the rolls, an adequatelifting force is provided for insuring a practically simultaneous contact with both of the magnetiorolls in the same feeding plane, so that sufficient magnetic attraction will be applied to hold the forward end of the sheet elevated, and to instantly feed it forward,

without, however, applying excessive magnetic force which might exert an appreciable drag in resisting the release of the sheet as its trailing edge came into register with the magnetic roll.

While the invention has been described with particularity as to detail, it is not the intention, unless otherwise indicated in the claims, to limit the invention to the specific mechanism in the form shown, since mfilificationsmay be made in the details thereof without departing from the spirit of the invention.

I claim: Y 1. In sheet feeding mechanism, the combinaand means for rotating the magnetic rolls in unison and in the same direction, lifting mechanism associated with the magnetic rolls and comprising a plurality of vacuum cups adapted in unison to make contact with the uppermost sheet of a stack at widely separated points of contact,

a fluid pressure cylinder for raising and lowering.

the vacuum cups in unison to elevate the uppermost sheet of the stack intofeeding contact with the magnetic rolls and biting roller means presenting its bite in the feeding plane of the magnetic rolls.

2. In sheet feeding mechanism, the combination of means for supporting a stack of sheets, a series of magnetic rolls located transversely above the forward end of the stack, means for rotating the magnetic rolls in unison to feed the sheets forward singly, and elevating mechanism in the form of a frame having four legs each provided at its lower end with a vacuum cup, a piston connected with the frame and a cylinder within which the piston is located, and means for admitting fluid pressure to each end of the cylinder to actuate the piston to effect raising and lowering movements of the elevating frame to cause engagement of the vacuum cups in unison with the uppermost sheet of the stack and to bring the sheets singly into simultaneous contact with the magnetic rolls. 7

3. In sheet feeding mechanism, the combination of means for supporting a stack of sheets, a

' series of magnetic rolls located transversely above the forward end of the stack, means for rotating the magnetic rolls in unison to feed the sheets forward singly, and elevating mechanism in the 1 form of a frame having four legs each provided at its lower end with a vacuum cup, the two forward cups being located intermediate the magnetic rolls and the two rear cups to the rear of the magnetic rolls, a piston connected with the frame and a cylinder within which the piston is located, and means for admitting fluid pressure to each end of the cylinder to actuate the piston to effect raising and lowering movements of the elevating frame to cause engagement of the vacuum cups in unison with the uppermost sheet of the stack and to bring the sheets singly into simultaneous contact with the magnetic rolls.

4. In sheet feeding mechanism, the combination of means for supporting a stack of sheets, a

series of magnetic rolls located transversely above the forward end of the'stack, means for rotating the magnetic rolls in unison to feed the sheets forward singly, and elevating mechanism in the form-of a frame having four legs each provided at its lower end with a vacuum cup, the two forward cups being located intermediate the magnetic rolls and the two rear cups to the rear of the magnetic rolls, and means adapted to effect raising and lowering movements of the elevating frame to cause engagement of the vacuum cups in unison with the uppermost sheet of the stack and to bring the sheets singly into simultaneous contact with the magnetic rolls.

' HARRY W. THEISS. 

